|Greatest Chemistry Discoveries
Science of Matter - The Central Science
The emergence of chemistry in Europe was primarily due to the recurrent incidence of the plague and blights there during the so called Dark Ages.
This gave rise to a need for medicines. It was thought that there exists a universal medicine called the Elixir of Life that can cure all diseases, but it was never found.
Chemistry is the science of matter, especially its properties, structure, composition, behavior, reactions, interactions and the changes it undergoes.
Chemistry is sometimes called "the central science" because it connects physics with other natural sciences such as astronomy, geology and biology.
Physics also studies matter, but physics is the science of quantities of space and matter, and laws governing them. Chemistry is a branch of physical science but not a branch of physics.
However, chemistry utilizes physics. For example, chemistry uses quantities like energy and entropy in relation to the spontaneity of chemical processes.
It also explains the structure and properties of matter as a consequence of the physical properties of chemical substances and their interactions.
For example, steel is harder than iron because its atoms are bound together in a more rigid crystalline lattice; wood burns or undergoes rapid oxidation because it can react spontaneously with oxygen in a chemical reaction above a certain temperature; sugar and salt dissolve in water because their molecular/ionic properties are such that dissolution is preferred under the ambient conditions.
Synthesis is the major aspect that separates chemistry from physics and biology as sciences. Chemistry includes the knowledge (science) to design and make more complex substances from simpler ones.
These new substances might then be analyzed for their physical or biological properties. The etymology of the word chemistry has been much disputed.
The genesis of chemistry can be traced to certain practices, known as alchemy, which had been practiced for several millennia in various parts of the world, particularly the Middle East.
1. Oxygen (1770s)
Joseph Priestley discovers oxygen; later, Antoine
Lavoisier clarifies the nature of elements. Priestley produces oxygen in
experiments and describes its role in combustion and respiration. Then,
by dissolving fixed air in water, he invents carbonated water.
Priestley, oblivious to the importance of his discovery, calls the new
gas "dephlogisticated air." Lavoisier gives oxygen its name and
correctly describes its role in combustion. Lavoisier then works with
others to devise a chemical nomenclature, which serves as the basis of
the modern system.
2. Atomic Theory (1808)
provides a way of linking invisible atoms to measurable quantities like
the volume of a gas or mass of a mineral. His atomic theory states that
elements consist of tiny particles called atoms. Thus, a pure element
consists of identical atoms, all with the same mass, and compounds
consist of atoms of different elements combined together.
3. Atoms Combine Into Molecules (1811 onward)
chemist Amedeo Avogadro finds that the atoms in elements combine to
form molecules. Avogadro proposes that equal volumes of gases under
equal conditions of temperature and pressure contain equal numbers of
4. Synthesis of Urea (1828)
accidentally synthesizes urea from inorganic materials, proving that
substances made by living things can be reproduced with nonliving
substances. Until 1828, it was believed that organic substances could
only form with the help of the "vital force" present in animals and
5. Chemical Structure (1850s)
Friedrich Kekule figures
out the chemical structure of benzene, bringing the study of molecular
structure to the forefront of chemistry. He writes that after years of
studying the nature of carbon-carbon bonds, he came up with the ring
shape of the benzene molecule after dreaming of a snake seizing its own
tail. The unusual structure solves the problem of how carbon atoms can
bond with up to four other atoms at the same time.
6. Periodic Table of the Elements (1860s –– 1870s)
Mendeleyev realizes that if all of the 63 known elements are arranged
in order of increasing atomic weight, their properties are repeated
according to certain periodic cycles. He formulates the periodic table
of the elements and predicts the existence of elements that have not yet
been discovered. Three of those elements are found during his lifetime:
gallium, scandium and germanium.
7. Electricity Transforms Chemicals (1807 –– 1810)
Davy finds that electricity transforms chemicals. He uses an electric
pile (an early battery) to separate salts by a process now known as
electrolysis. With many batteries he is able to separate elemental
potassium and sodium in calcium, strontium, barium and magnesium.
8. The Electron (1897)
Thomson discovers that the negatively charged particles emitted by
cathode ray tubes are smaller than atoms and part of all atoms. He calls
these particles, now known as electrons, "corpuscles."
9. Electrons for Chemical Bonds (1913 onward)
Bohr publishes his model of atomic structure in which electrons travel
in specific orbits around the nucleus, and the chemical properties of an
element are largely determined by the number of electrons in its atoms'
outer orbits. This paves the way to an understanding of how electrons
are involved in chemical bonding.
10. Atoms Have Signatures of Light (1850s)
Kirchhoff and Robert Bunsen find that each element absorbs or emits
light at specific wavelengths, producing specific spectra.
11. Radioactivity (1890s –– 1900s)
and Pierre Curie discover and isolate radioactive materials. After
chemically extracting uranium from uranium ore, Marie notes the residual
material is more "active" than the pure uranium. She concludes that the
ore contains, in addition to uranium, new elements that are also
radioactive. This leads to the discovery of the elements polonium and
12. Plastics (1869 and 1900s)
John Wesley Hyatt
formulates celluloid plastic for use as a substitute for ivory in the
manufacture of billiard balls. Celluloid is the first important
synthetic plastic and is used as a substitute for expensive substances
such as ivory, amber, horn and tortoiseshell. Later, Leo Baekeland
invents hardened plastics, specifically Bakelite, a synthetic substitute
for the shellac used in electronic insulation.
13. Fullerenes (1985)
Curl, Harold Kroto and Rick Smalley discover an entirely new class of
carbon compound with a cage-like structure. This leads to the discovery
of similar tube-like carbon structures. Collectively, the compounds come
to be called buckminsterfullerenes, or fullerenes. The molecules are
composed entirely of carbon and take the form of a hollow sphere,
ellipsoid, tube or ring. Named for Richard Buckminster Fuller, the
architect who created the geodesic dome, they are sometimes called
"buckyballs" or "buckytubes."